As anyone who has traveled to Milford Sound in the Fiordland National Park on the southwestern side of New Zealand’s South Island will know, the further up the Hollyford Valley you travel, the steeper the surrounding mountains get. They loom above you as you approach the famous Homer Tunnel. In winter this road can become impassable because of snow avalanches cascading down the near vertical mountain faces. In spring, as the snow thaws, rock avalanches can also close the road as a result of ice shattering rock during the winter freeze.
This extract from from the New Zealand topographical map of the area clearly shows the gradients of the surrounding mountains. (Click on link for larger view)
It was at the eastern entrance to the Homer Tunnel that these images were taken. The tunnel is the only way through the mountains to reach the Milford Sound by road. Entrance to the tunnel is controlled by traffic lights as there is just a 1.2 km single lane road through the Darren Mountains at the Homer Saddle. Until 1954 there was no road access to the Milford Sound.
On the day we left Milford Sound via the Cleddau Valley and through the Homer Tunnel it became more overcast as we climbed further into the mountains. By the time we reached the tunnel it was threatening to rain and the temperature had dropped considerably. As we exited the tunnel and into the beginning of the Hollyford Valley we were presented with these views.